--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-2.6.1/Doc/library/io.rst Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,652 @@
+:mod:`io` --- Core tools for working with streams
+=================================================
+
+.. module:: io
+ :synopsis: Core tools for working with streams.
+.. moduleauthor:: Guido van Rossum <guido@python.org>
+.. moduleauthor:: Mike Verdone <mike.verdone@gmail.com>
+.. moduleauthor:: Mark Russell <mark.russell@zen.co.uk>
+.. sectionauthor:: Benjamin Peterson
+.. versionadded:: 2.6
+
+The :mod:`io` module provides the Python interfaces to stream handling. The
+builtin :func:`open` function is defined in this module.
+
+At the top of the I/O hierarchy is the abstract base class :class:`IOBase`. It
+defines the basic interface to a stream. Note, however, that there is no
+seperation between reading and writing to streams; implementations are allowed
+to throw an :exc:`IOError` if they do not support a given operation.
+
+Extending :class:`IOBase` is :class:`RawIOBase` which deals simply with the
+reading and writing of raw bytes to a stream. :class:`FileIO` subclasses
+:class:`RawIOBase` to provide an interface to files in the machine's
+file system.
+
+:class:`BufferedIOBase` deals with buffering on a raw byte stream
+(:class:`RawIOBase`). Its subclasses, :class:`BufferedWriter`,
+:class:`BufferedReader`, and :class:`BufferedRWPair` buffer streams that are
+readable, writable, and both readable and writable.
+:class:`BufferedRandom` provides a buffered interface to random access
+streams. :class:`BytesIO` is a simple stream of in-memory bytes.
+
+Another :class:`IOBase` subclass, :class:`TextIOBase`, deals with
+streams whose bytes represent text, and handles encoding and decoding
+from and to strings. :class:`TextIOWrapper`, which extends it, is a
+buffered text interface to a buffered raw stream
+(:class:`BufferedIOBase`). Finally, :class:`StringIO` is an in-memory
+stream for text.
+
+Argument names are not part of the specification, and only the arguments of
+:func:`open` are intended to be used as keyword arguments.
+
+
+Module Interface
+----------------
+
+.. data:: DEFAULT_BUFFER_SIZE
+
+ An int containing the default buffer size used by the module's buffered I/O
+ classes. :func:`open` uses the file's blksize (as obtained by
+ :func:`os.stat`) if possible.
+
+.. function:: open(file[, mode[, buffering[, encoding[, errors[, newline[, closefd=True]]]]]])
+
+ Open *file* and return a stream. If the file cannot be opened, an
+ :exc:`IOError` is raised.
+
+ *file* is either a string giving the name (and the path if the file isn't in
+ the current working directory) of the file to be opened or a file
+ descriptor of the file to be opened. (If a file descriptor is given,
+ for example, from :func:`os.fdopen`, it is closed when the returned
+ I/O object is closed, unless *closefd* is set to ``False``.)
+
+ *mode* is an optional string that specifies the mode in which the file is
+ opened. It defaults to ``'r'`` which means open for reading in text mode.
+ Other common values are ``'w'`` for writing (truncating the file if it
+ already exists), and ``'a'`` for appending (which on *some* Unix systems,
+ means that *all* writes append to the end of the file regardless of the
+ current seek position). In text mode, if *encoding* is not specified the
+ encoding used is platform dependent. (For reading and writing raw bytes use
+ binary mode and leave *encoding* unspecified.) The available modes are:
+
+ ========= ===============================================================
+ Character Meaning
+ --------- ---------------------------------------------------------------
+ ``'r'`` open for reading (default)
+ ``'w'`` open for writing, truncating the file first
+ ``'a'`` open for writing, appending to the end of the file if it exists
+ ``'b'`` binary mode
+ ``'t'`` text mode (default)
+ ``'+'`` open a disk file for updating (reading and writing)
+ ``'U'`` universal newline mode (for backwards compatibility; should
+ not be used in new code)
+ ========= ===============================================================
+
+ The default mode is ``'rt'`` (open for reading text). For binary random
+ access, the mode ``'w+b'`` opens and truncates the file to 0 bytes, while
+ ``'r+b'`` opens the file without truncation.
+
+ Python distinguishes between files opened in binary and text modes, even when
+ the underlying operating system doesn't. Files opened in binary mode
+ (including ``'b'`` in the *mode* argument) return contents as ``bytes``
+ objects without any decoding. In text mode (the default, or when ``'t'`` is
+ included in the *mode* argument), the contents of the file are returned as
+ strings, the bytes having been first decoded using a platform-dependent
+ encoding or using the specified *encoding* if given.
+
+ *buffering* is an optional integer used to set the buffering policy. By
+ default full buffering is on. Pass 0 to switch buffering off (only allowed
+ in binary mode), 1 to set line buffering, and an integer > 1 for full
+ buffering.
+
+ *encoding* is the name of the encoding used to decode or encode the file.
+ This should only be used in text mode. The default encoding is platform
+ dependent, but any encoding supported by Python can be used. See the
+ :mod:`codecs` module for the list of supported encodings.
+
+ *errors* is an optional string that specifies how encoding and decoding
+ errors are to be handled. Pass ``'strict'`` to raise a :exc:`ValueError`
+ exception if there is an encoding error (the default of ``None`` has the same
+ effect), or pass ``'ignore'`` to ignore errors. (Note that ignoring encoding
+ errors can lead to data loss.) ``'replace'`` causes a replacement marker
+ (such as ``'?'``) to be inserted where there is malformed data. When
+ writing, ``'xmlcharrefreplace'`` (replace with the appropriate XML character
+ reference) or ``'backslashreplace'`` (replace with backslashed escape
+ sequences) can be used. Any other error handling name that has been
+ registered with :func:`codecs.register_error` is also valid.
+
+ *newline* controls how universal newlines works (it only applies to text
+ mode). It can be ``None``, ``''``, ``'\n'``, ``'\r'``, and ``'\r\n'``. It
+ works as follows:
+
+ * On input, if *newline* is ``None``, universal newlines mode is enabled.
+ Lines in the input can end in ``'\n'``, ``'\r'``, or ``'\r\n'``, and these
+ are translated into ``'\n'`` before being returned to the caller. If it is
+ ``''``, universal newline mode is enabled, but line endings are returned to
+ the caller untranslated. If it has any of the other legal values, input
+ lines are only terminated by the given string, and the line ending is
+ returned to the caller untranslated.
+
+ * On output, if *newline* is ``None``, any ``'\n'`` characters written are
+ translated to the system default line separator, :data:`os.linesep`. If
+ *newline* is ``''``, no translation takes place. If *newline* is any of
+ the other legal values, any ``'\n'`` characters written are translated to
+ the given string.
+
+ If *closefd* is ``False`` and a file descriptor rather than a
+ filename was given, the underlying file descriptor will be kept open
+ when the file is closed. If a filename is given *closefd* has no
+ effect but must be ``True`` (the default).
+
+ The type of file object returned by the :func:`open` function depends
+ on the mode. When :func:`open` is used to open a file in a text mode
+ (``'w'``, ``'r'``, ``'wt'``, ``'rt'``, etc.), it returns a
+ :class:`TextIOWrapper`. When used to open a file in a binary mode,
+ the returned class varies: in read binary mode, it returns a
+ :class:`BufferedReader`; in write binary and append binary modes, it
+ returns a :class:`BufferedWriter`, and in read/write mode, it returns
+ a :class:`BufferedRandom`.
+
+ It is also possible to use a string or bytearray as a file for both reading
+ and writing. For strings :class:`StringIO` can be used like a file opened in
+ a text mode, and for bytearrays a :class:`BytesIO` can be used like a
+ file opened in a binary mode.
+
+
+.. exception:: BlockingIOError
+
+ Error raised when blocking would occur on a non-blocking stream. It inherits
+ :exc:`IOError`.
+
+ In addition to those of :exc:`IOError`, :exc:`BlockingIOError` has one
+ attribute:
+
+ .. attribute:: characters_written
+
+ An integer containing the number of characters written to the stream
+ before it blocked.
+
+
+.. exception:: UnsupportedOperation
+
+ An exception inheriting :exc:`IOError` and :exc:`ValueError` that is raised
+ when an unsupported operation is called on a stream.
+
+
+I/O Base Classes
+----------------
+
+.. class:: IOBase
+
+ The abstract base class for all I/O classes, acting on streams of bytes.
+ There is no public constructor.
+
+ This class provides empty abstract implementations for many methods
+ that derived classes can override selectively; the default
+ implementations represent a file that cannot be read, written or
+ seeked.
+
+ Even though :class:`IOBase` does not declare :meth:`read`, :meth:`readinto`,
+ or :meth:`write` because their signatures will vary, implementations and
+ clients should consider those methods part of the interface. Also,
+ implementations may raise a :exc:`IOError` when operations they do not
+ support are called.
+
+ The basic type used for binary data read from or written to a file is
+ :class:`bytes`. :class:`bytearray`\s are accepted too, and in some cases
+ (such as :class:`readinto`) required. Text I/O classes work with
+ :class:`str` data.
+
+ Note that calling any method (even inquiries) on a closed stream is
+ undefined. Implementations may raise :exc:`IOError` in this case.
+
+ IOBase (and its subclasses) support the iterator protocol, meaning that an
+ :class:`IOBase` object can be iterated over yielding the lines in a stream.
+
+ IOBase is also a context manager and therefore supports the
+ :keyword:`with` statement. In this example, *file* is closed after the
+ :keyword:`with` statement's suite is finished---even if an exception occurs::
+
+ with open('spam.txt', 'w') as file:
+ file.write('Spam and eggs!')
+
+ :class:`IOBase` provides these data attributes and methods:
+
+ .. method:: close()
+
+ Flush and close this stream. This method has no effect if the file is
+ already closed.
+
+ .. attribute:: closed
+
+ True if the stream is closed.
+
+ .. method:: fileno()
+
+ Return the underlying file descriptor (an integer) of the stream if it
+ exists. An :exc:`IOError` is raised if the IO object does not use a file
+ descriptor.
+
+ .. method:: flush()
+
+ Flush the write buffers of the stream if applicable. This does nothing
+ for read-only and non-blocking streams.
+
+ .. method:: isatty()
+
+ Return ``True`` if the stream is interactive (i.e., connected to
+ a terminal/tty device).
+
+ .. method:: readable()
+
+ Return ``True`` if the stream can be read from. If False, :meth:`read`
+ will raise :exc:`IOError`.
+
+ .. method:: readline([limit])
+
+ Read and return one line from the stream. If *limit* is specified, at
+ most *limit* bytes will be read.
+
+ The line terminator is always ``b'\n'`` for binary files; for text files,
+ the *newlines* argument to :func:`open` can be used to select the line
+ terminator(s) recognized.
+
+ .. method:: readlines([hint])
+
+ Read and return a list of lines from the stream. *hint* can be specified
+ to control the number of lines read: no more lines will be read if the
+ total size (in bytes/characters) of all lines so far exceeds *hint*.
+
+ .. method:: seek(offset[, whence])
+
+ Change the stream position to the given byte *offset*. *offset* is
+ interpreted relative to the position indicated by *whence*. Values for
+ *whence* are:
+
+ * ``0`` -- start of the stream (the default); *offset* should be zero or positive
+ * ``1`` -- current stream position; *offset* may be negative
+ * ``2`` -- end of the stream; *offset* is usually negative
+
+ Return the new absolute position.
+
+ .. method:: seekable()
+
+ Return ``True`` if the stream supports random access. If ``False``,
+ :meth:`seek`, :meth:`tell` and :meth:`truncate` will raise :exc:`IOError`.
+
+ .. method:: tell()
+
+ Return the current stream position.
+
+ .. method:: truncate([size])
+
+ Truncate the file to at most *size* bytes. *size* defaults to the current
+ file position, as returned by :meth:`tell`.
+
+ .. method:: writable()
+
+ Return ``True`` if the stream supports writing. If ``False``,
+ :meth:`write` and :meth:`truncate` will raise :exc:`IOError`.
+
+ .. method:: writelines(lines)
+
+ Write a list of lines to the stream. Line separators are not added, so it
+ is usual for each of the lines provided to have a line separator at the
+ end.
+
+
+.. class:: RawIOBase
+
+ Base class for raw binary I/O. It inherits :class:`IOBase`. There is no
+ public constructor.
+
+ In addition to the attributes and methods from :class:`IOBase`,
+ RawIOBase provides the following methods:
+
+ .. method:: read([n])
+
+ Read and return all the bytes from the stream until EOF, or if *n* is
+ specified, up to *n* bytes. Only one system call is ever made. An empty
+ bytes object is returned on EOF; ``None`` is returned if the object is set
+ not to block and has no data to read.
+
+ .. method:: readall()
+
+ Read and return all the bytes from the stream until EOF, using multiple
+ calls to the stream if necessary.
+
+ .. method:: readinto(b)
+
+ Read up to len(b) bytes into bytearray *b* and return the number of bytes
+ read.
+
+ .. method:: write(b)
+
+ Write the given bytes or bytearray object, *b*, to the underlying raw
+ stream and return the number of bytes written (This is never less than
+ ``len(b)``, since if the write fails, an :exc:`IOError` will be raised).
+
+
+Raw File I/O
+------------
+
+.. class:: FileIO(name[, mode])
+
+ :class:`FileIO` represents a file containing bytes data. It implements
+ the :class:`RawIOBase` interface (and therefore the :class:`IOBase`
+ interface, too).
+
+ The *mode* can be ``'r'``, ``'w'`` or ``'a'`` for reading (default), writing,
+ or appending. The file will be created if it doesn't exist when opened for
+ writing or appending; it will be truncated when opened for writing. Add a
+ ``'+'`` to the mode to allow simultaneous reading and writing.
+
+ In addition to the attributes and methods from :class:`IOBase` and
+ :class:`RawIOBase`, :class:`FileIO` provides the following data
+ attributes and methods:
+
+ .. attribute:: mode
+
+ The mode as given in the constructor.
+
+ .. attribute:: name
+
+ The file name. This is the file descriptor of the file when no name is
+ given in the constructor.
+
+ .. method:: read([n])
+
+ Read and return at most *n* bytes. Only one system call is made, so it is
+ possible that less data than was requested is returned. Use :func:`len`
+ on the returned bytes object to see how many bytes were actually returned.
+ (In non-blocking mode, ``None`` is returned when no data is available.)
+
+ .. method:: readall()
+
+ Read and return the entire file's contents in a single bytes object. As
+ much as immediately available is returned in non-blocking mode. If the
+ EOF has been reached, ``b''`` is returned.
+
+ .. method:: write(b)
+
+ Write the bytes or bytearray object, *b*, to the file, and return
+ the number actually written. Only one system call is made, so it
+ is possible that only some of the data is written.
+
+ Note that the inherited ``readinto()`` method should not be used on
+ :class:`FileIO` objects.
+
+
+Buffered Streams
+----------------
+
+.. class:: BufferedIOBase
+
+ Base class for streams that support buffering. It inherits :class:`IOBase`.
+ There is no public constructor.
+
+ The main difference with :class:`RawIOBase` is that the :meth:`read` method
+ supports omitting the *size* argument, and does not have a default
+ implementation that defers to :meth:`readinto`.
+
+ In addition, :meth:`read`, :meth:`readinto`, and :meth:`write` may raise
+ :exc:`BlockingIOError` if the underlying raw stream is in non-blocking mode
+ and not ready; unlike their raw counterparts, they will never return
+ ``None``.
+
+ A typical implementation should not inherit from a :class:`RawIOBase`
+ implementation, but wrap one like :class:`BufferedWriter` and
+ :class:`BufferedReader`.
+
+ :class:`BufferedIOBase` provides or overrides these methods in addition to
+ those from :class:`IOBase`:
+
+ .. method:: read([n])
+
+ Read and return up to *n* bytes. If the argument is omitted, ``None``, or
+ negative, data is read and returned until EOF is reached. An empty bytes
+ object is returned if the stream is already at EOF.
+
+ If the argument is positive, and the underlying raw stream is not
+ interactive, multiple raw reads may be issued to satisfy the byte count
+ (unless EOF is reached first). But for interactive raw streams, at most
+ one raw read will be issued, and a short result does not imply that EOF is
+ imminent.
+
+ A :exc:`BlockingIOError` is raised if the underlying raw stream has no
+ data at the moment.
+
+ .. method:: readinto(b)
+
+ Read up to len(b) bytes into bytearray *b* and return the number of bytes
+ read.
+
+ Like :meth:`read`, multiple reads may be issued to the underlying raw
+ stream, unless the latter is 'interactive.'
+
+ A :exc:`BlockingIOError` is raised if the underlying raw stream has no
+ data at the moment.
+
+ .. method:: write(b)
+
+ Write the given bytes or bytearray object, *b*, to the underlying raw
+ stream and return the number of bytes written (never less than ``len(b)``,
+ since if the write fails an :exc:`IOError` will be raised).
+
+ A :exc:`BlockingIOError` is raised if the buffer is full, and the
+ underlying raw stream cannot accept more data at the moment.
+
+
+.. class:: BytesIO([initial_bytes])
+
+ A stream implementation using an in-memory bytes buffer. It inherits
+ :class:`BufferedIOBase`.
+
+ The argument *initial_bytes* is an optional initial bytearray.
+
+ :class:`BytesIO` provides or overrides these methods in addition to those
+ from :class:`BufferedIOBase` and :class:`IOBase`:
+
+ .. method:: getvalue()
+
+ Return ``bytes`` containing the entire contents of the buffer.
+
+ .. method:: read1()
+
+ In :class:`BytesIO`, this is the same as :meth:`read`.
+
+ .. method:: truncate([size])
+
+ Truncate the buffer to at most *size* bytes. *size* defaults to the
+ current stream position, as returned by :meth:`tell`.
+
+
+.. class:: BufferedReader(raw[, buffer_size])
+
+ A buffer for a readable, sequential :class:`RawIOBase` object. It inherits
+ :class:`BufferedIOBase`.
+
+ The constructor creates a :class:`BufferedReader` for the given readable
+ *raw* stream and *buffer_size*. If *buffer_size* is omitted,
+ :data:`DEFAULT_BUFFER_SIZE` is used.
+
+ :class:`BufferedReader` provides or overrides these methods in addition to
+ those from :class:`BufferedIOBase` and :class:`IOBase`:
+
+ .. method:: peek([n])
+
+ Return 1 (or *n* if specified) bytes from a buffer without advancing the
+ position. Only a single read on the raw stream is done to satisfy the
+ call. The number of bytes returned may be less than requested since at
+ most all the buffer's bytes from the current position to the end are
+ returned.
+
+ .. method:: read([n])
+
+ Read and return *n* bytes, or if *n* is not given or negative, until EOF
+ or if the read call would block in non-blocking mode.
+
+ .. method:: read1(n)
+
+ Read and return up to *n* bytes with only one call on the raw stream. If
+ at least one byte is buffered, only buffered bytes are returned.
+ Otherwise, one raw stream read call is made.
+
+
+.. class:: BufferedWriter(raw[, buffer_size[, max_buffer_size]])
+
+ A buffer for a writeable sequential RawIO object. It inherits
+ :class:`BufferedIOBase`.
+
+ The constructor creates a :class:`BufferedWriter` for the given writeable
+ *raw* stream. If the *buffer_size* is not given, it defaults to
+ :data:`DEAFULT_BUFFER_SIZE`. If *max_buffer_size* is omitted, it defaults to
+ twice the buffer size.
+
+ :class:`BufferedWriter` provides or overrides these methods in addition to
+ those from :class:`BufferedIOBase` and :class:`IOBase`:
+
+ .. method:: flush()
+
+ Force bytes held in the buffer into the raw stream. A
+ :exc:`BlockingIOError` should be raised if the raw stream blocks.
+
+ .. method:: write(b)
+
+ Write the bytes or bytearray object, *b*, onto the raw stream and return
+ the number of bytes written. A :exc:`BlockingIOError` is raised when the
+ raw stream blocks.
+
+
+.. class:: BufferedRWPair(reader, writer[, buffer_size[, max_buffer_size]])
+
+ A combined buffered writer and reader object for a raw stream that can be
+ written to and read from. It has and supports both :meth:`read`, :meth:`write`,
+ and their variants. This is useful for sockets and two-way pipes.
+ It inherits :class:`BufferedIOBase`.
+
+ *reader* and *writer* are :class:`RawIOBase` objects that are readable and
+ writeable respectively. If the *buffer_size* is omitted it defaults to
+ :data:`DEFAULT_BUFFER_SIZE`. The *max_buffer_size* (for the buffered writer)
+ defaults to twice the buffer size.
+
+ :class:`BufferedRWPair` implements all of :class:`BufferedIOBase`\'s methods.
+
+
+.. class:: BufferedRandom(raw[, buffer_size[, max_buffer_size]])
+
+ A buffered interface to random access streams. It inherits
+ :class:`BufferedReader` and :class:`BufferedWriter`.
+
+ The constructor creates a reader and writer for a seekable raw stream, given
+ in the first argument. If the *buffer_size* is omitted it defaults to
+ :data:`DEFAULT_BUFFER_SIZE`. The *max_buffer_size* (for the buffered writer)
+ defaults to twice the buffer size.
+
+ :class:`BufferedRandom` is capable of anything :class:`BufferedReader` or
+ :class:`BufferedWriter` can do.
+
+
+Text I/O
+--------
+
+.. class:: TextIOBase
+
+ Base class for text streams. This class provides a character and line based
+ interface to stream I/O. There is no :meth:`readinto` method because
+ Python's character strings are immutable. It inherits :class:`IOBase`.
+ There is no public constructor.
+
+ :class:`TextIOBase` provides or overrides these data attributes and
+ methods in addition to those from :class:`IOBase`:
+
+ .. attribute:: encoding
+
+ The name of the encoding used to decode the stream's bytes into
+ strings, and to encode strings into bytes.
+
+ .. attribute:: newlines
+
+ A string, a tuple of strings, or ``None``, indicating the newlines
+ translated so far.
+
+ .. method:: read(n)
+
+ Read and return at most *n* characters from the stream as a single
+ :class:`str`. If *n* is negative or ``None``, reads to EOF.
+
+ .. method:: readline()
+
+ Read until newline or EOF and return a single ``str``. If the stream is
+ already at EOF, an empty string is returned.
+
+ .. method:: write(s)
+
+ Write the string *s* to the stream and return the number of characters
+ written.
+
+
+.. class:: TextIOWrapper(buffer[, encoding[, errors[, newline[, line_buffering]]]])
+
+ A buffered text stream over a :class:`BufferedIOBase` raw stream, *buffer*.
+ It inherits :class:`TextIOBase`.
+
+ *encoding* gives the name of the encoding that the stream will be decoded or
+ encoded with. It defaults to :func:`locale.getpreferredencoding`.
+
+ *errors* is an optional string that specifies how encoding and decoding
+ errors are to be handled. Pass ``'strict'`` to raise a :exc:`ValueError`
+ exception if there is an encoding error (the default of ``None`` has the same
+ effect), or pass ``'ignore'`` to ignore errors. (Note that ignoring encoding
+ errors can lead to data loss.) ``'replace'`` causes a replacement marker
+ (such as ``'?'``) to be inserted where there is malformed data. When
+ writing, ``'xmlcharrefreplace'`` (replace with the appropriate XML character
+ reference) or ``'backslashreplace'`` (replace with backslashed escape
+ sequences) can be used. Any other error handling name that has been
+ registered with :func:`codecs.register_error` is also valid.
+
+ *newline* can be ``None``, ``''``, ``'\n'``, ``'\r'``, or ``'\r\n'``. It
+ controls the handling of line endings. If it is ``None``, universal newlines
+ is enabled. With this enabled, on input, the lines endings ``'\n'``,
+ ``'\r'``, or ``'\r\n'`` are translated to ``'\n'`` before being returned to
+ the caller. Conversely, on output, ``'\n'`` is translated to the system
+ default line seperator, :data:`os.linesep`. If *newline* is any other of its
+ legal values, that newline becomes the newline when the file is read and it
+ is returned untranslated. On output, ``'\n'`` is converted to the *newline*.
+
+ If *line_buffering* is ``True``, :meth:`flush` is implied when a call to
+ write contains a newline character.
+
+ :class:`TextIOWrapper` provides these data attributes in addition to those of
+ :class:`TextIOBase` and its parents:
+
+ .. attribute:: errors
+
+ The encoding and decoding error setting.
+
+ .. attribute:: line_buffering
+
+ Whether line buffering is enabled.
+
+
+.. class:: StringIO([initial_value[, encoding[, errors[, newline]]]])
+
+ An in-memory stream for text. It in inherits :class:`TextIOWrapper`.
+
+ Create a new StringIO stream with an inital value, encoding, error handling,
+ and newline setting. See :class:`TextIOWrapper`\'s constructor for more
+ information.
+
+ :class:`StringIO` provides this method in addition to those from
+ :class:`TextIOWrapper` and its parents:
+
+ .. method:: getvalue()
+
+ Return a ``str`` containing the entire contents of the buffer.
+
+
+.. class:: IncrementalNewlineDecoder
+
+ A helper codec that decodes newlines for universal newlines mode. It
+ inherits :class:`codecs.IncrementalDecoder`.
+